Not to make this an endless thread, but I have been wondering about what's the most rsync-friendly backup on-disk layout. I have found Borg to have less files and directories which I would naively think translates to less checks (and the files are not huge, too). I have tried Kopia and Bupstash as well but they both produce a lot of files and directories, much more than Borg. So I think Borg wins at this but I haven't checked Restic and the various Duplic[ati|icity|whatever-else] programs in a while (last I did at least a year ago).
I think the advantage of restic is that you don't need to rsync afterwards, it handles all that for you. Combined with its FUSE backup decryption (it mounts the remote backup as a local filesystem you can restore files from), it's very set-and-forget.
My problem with Restic was that it did not recognize sub-second timestamps of files. I made test scripts that tested it (and were creating files and directories in a hypothetical backup source, and were also changing the files) but then Restic insisted nothing was changed because the changes were happening too fast.
I modified the scripts to do `sleep 1` between each change but it left a sour taste and I never gave Restic a fair chance. I see a good amount of praise in this thread, I'll definitely revisit it when I get a little free time and energy.
Because yeah, it's not expected you'll make a second backup snapshots <1s after the first one. :D
I tried Restic again but, its repo size is 2x of that of Borg which allows you to fine-tune compression, and Restic doesn't.
So I'll keep an eye on Rustic instead (it is much faster on some hot paths + allows you to specify base path of the backup; long story but I need that feature a lot because I also do copies of my stuff to network disks and when you backup from there you want to rewrite the path inside the backup snapshot).
Rustic compresses equivalently to Borg which is not a surprise because both use zstd on the same compression level.
